clc
clear
u = 10;
t = 1:500;
alpha = .6;

x1 = t.*t*cot(alpha/2);
figure,plot(t,x1)

x2 = j*u.*t*(1/cos(alpha));
figure,plot(t,x2)

x = exp(j*(x1-j*x2));
plot(t,x)